JPH11200261A - Finishing of cotton product such as jeans - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for finishing a cotton product such as jeans semipermanently having a wild taste and an unconventional visual feeling without becoming pure white even by repeating washing. SOLUTION: The characteristic of this method for finishing a cotton product such as jeans comprises reacting nitric acid with the cotton product such as the jeans or its fabric and then neutralizing the resultant product or fabric with a basic substance. The nitric acid concentration is 0.5-67.5%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing cotton products such as jeans in which the fabric after bleaching has an unprecedented pale yellow color, as well as the bleaching (bleaching, bleaching) of dyes.

[0002]

2. Description of the Related Art Various types of bleaching of jeans have been conventionally performed using chlorine, ozone, and potassium permanganate. Although these improvements have been made, the characteristic is that the hue of the jeans fabric after bleaching and decomposing the indigo dye is bleached to become white. Although bleached products bleached with these oxidizing agents differ depending on the chemicals and methods, their strength is remarkably reduced, leading to a reduction in commercial value.

[0003]

As described above, according to the conventional bleaching method, even if a cotton product such as jeans becomes white, or even a partially bleached product which has been decolorized to a certain extent, the whiteness is increased as the washing is repeated or used. Partially exposed, especially colorless (produced) pants products have the disadvantage that consumers can become "white jeans" after several washes after purchase, impairing the flavor of wild produce. For this reason, conventionally, it has been countered by dyeing the resulting color with a dye or the like. The present invention solves the difficulties of the conventional bleaching method, and produces cotton products such as jeans and the like, which have a semi-permanent wild taste without being white even after repeated washing and have an unprecedented texture. It is intended to provide a possible processing method.

[0004]

As a result of studying the above problems, a cotton product such as jeans is characterized in that nitric acid is allowed to act on a cotton product such as jeans or a fabric thereof and then neutralized with a basic substance. Processing method. The cotton products such as jeans or fabrics thereof include not only indigo dyed denim but also various dyes, dyed materials dyed with a face, original white fabric, and sewn products thereof.

The nitric acid concentration varies depending on the material and the fastness of dyes such as indigo dyes, but is 0.5 to 67.5%, preferably 10 to 10%.
~ 30%. If the nitric acid concentration is 0.5% or less, the reaction does not proceed easily. Also, even if the nitric acid concentration is 60% or more, low temperature (25 ° C),
If it is short (5 to 10 seconds), there is no problem in strength and elongation. A commercially available maximum nitric acid concentration of 67.5% can be used as well. When 10% or more of nitric acid is reacted, the bleaching of the dye and the yellowing of the cellulose fiber easily proceed simultaneously. In the case of indigo dyeing with jeans fabric, a preferred degree of dye bleaching according to the nitric acid concentration is exhibited when the nitric acid concentration is in the range of 20 to 30%. From the concentration of nitric acid of about 45% to the maximum concentration, the dye can be completely decomposed, and semi-permanent yellowing processing of cotton fabrics such as jeans is possible.

[0006] The reaction time of nitric acid also depends on the nitric acid concentration and temperature and the bleaching degree of the dye. It is about 10 to 30 minutes. The temperature during the nitric acid action depends on the nitric acid concentration and the bleaching degree of the dye, but is preferably 25 to 60 ° C.

As the basic substance used for neutralization, a strong basic substance is not preferable because it causes damage to cellulose, and a weak basic substance usually used for neutralizing cellulosic fibers such as soda ash is used. preferable. However, short-time neutralization with a dilute solution of a strongly basic substance is not excluded.

[0008]

According to the processing method of the present invention, when a cotton product such as jeans is dyed,
As the dye is bleached, the cellulose of the fabric is nitrified, giving it a distinctive color. The degree of decolorization increases as the concentration of nitric acid increases, the reaction time increases, or the temperature during the reaction increases. In the most significant cases, the dye is completely decomposed and the nitrification reaction turns into a light brown cotton product.
In the case of non-dyed fabric, a nitrification reaction of the cotton product into cellulose results in a light brown cotton product.

EXAMPLE 1 A 30% aqueous nitric acid solution was prepared, and indigo-dyed denim fabric (jeans fabric) and white fabric before dyeing were immersed in the solution.
The reaction was performed for 15 minutes. Thereafter, the indigo dyed denim cloth and the white cloth before dyeing are immersed in 5 g / L of an aqueous soda ash solution,
The mixture was neutralized at 40 ° C. for 15 minutes. After neutralization, washing with water at 40 ° C. for 5 minutes was repeated twice, followed by dehydration and drying.

By the nitric acid treatment of Example 1, the indigo-dyed denim fabric is in a state in which the indigo dye is almost bleached, a little pale blue remains, and the fabric has a unique texture with a pale yellow color. Was.

Example 2 The nitric acid concentration was 10%, the liquid temperature was 70 ° C., and the other components were treated and bleached in the same manner as in Example 1. As a result of the above treatment, the indigo-dyed denim fabric was in a state in which the indigo dye was slightly bleached, and the white fabric became light brown, giving a cloth with a new texture. The light brown color did not become white jeans even after repeated washing. Light brown color was maintained semipermanently.

Example 3 The concentration of nitric acid was 1%, the temperature of the solution was 100 ° C., and the other components were treated and bleached in the same manner as in Example 1. As a result of the above-mentioned treatment, a cloth with a unique texture with slight discoloration and pale yellow was felt.

When the solution temperature and the reaction time are kept constant, the degree of bleaching is proportional to the nitric acid concentration. This is shown in FIG.
The conditions in this case are a liquid temperature of 25 ° C. and an immersion time of 10 minutes. It is the result of having tested with the indigo dyeing denim cloth. Indigo-dyed denim fabric is bleached up to almost 30% in proportion to nitric acid concentration. When the nitric acid concentration increases to around 30 to 40%, a slight pale blue remains, but the fabric has a unique color tone with a pale yellow color. If the concentration is further higher, the dye is completely decomposed and a light brown fabric is formed by the nitrification reaction. This bleaching is the same for denim after sewing.

The strength of the fabric was measured according to JIS L-1096. The sample was processed in Example 1. Table 1 shows the results. The strength reduction rate was about 10%, and a practically satisfactory result was obtained.

[0015]

[Table 1]

As is clear from the above examples, the present invention relates to a dye, a bleaching pigment by oxidative decomposition of nitric acid, a modification of cellulose surface by a nitrification reaction to cellulose specific to nitric acid, and a coloring (as a result, To give light brown color), physical properties, texture, surface feel (tactile sensation) of cellulose fibers, yarns and knitted fabrics
Special processing, such as keeping the same, is possible.

[0017]

According to the present invention, a cotton product such as jeans or its fabric can be adjusted to a desired optimum bleaching degree by a simple processing operation, and further, the fabric becomes light brown and has an unprecedented color tone. A textured product is obtained. Since this light brown does not become white jeans even by repeated washing, the light brown is kept semipermanently, and the natural, natural, and further generation texture of the ecology image is obtained,
This enables creation of a new product that has never existed before.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state of fading of a denim fabric when a treatment is performed while changing a nitric acid concentration.

Claims (2)

[Claims] 1. A method for processing cotton products such as jeans, wherein nitric acid is allowed to act on a cotton product such as jeans or a fabric thereof, and then neutralized with a basic substance. 2. The method according to claim 1, wherein the nitric acid concentration is 0.5 to 67.5%.
The processing method for cotton products such as the described jeans.